The present invention is directed to the mounting of a rotatable shaft with particular attention to the thrust loading and control thereof.
It is often advantageous to measure the thrust load carried by the thrust bearings of a rotating shaft. The monitoring of such loads can enable the operator to avoid damaging thrust conditions and thereby substantially extends the life of the bearings and other equipment subjected to these loads. Such devices have tended to be of marginal effectiveness unless they included very sophisticated measuring equipment for measuring the displacement of the shaft under axial load. This sophisticated equipment was necessary because of the very limited axial travel afforded such assemblies. Furthermore, thrust monitoring systems were often associated with propulsion devices such as screw shafts on ships and propeller shafts on airplanes. Consequently, these devices have been designed to sense thrust load only in one direction. For the foregoing reasons, early thrust metering devices have lacked the versatility, accuracy and reliability desired.
To overcome a number of the foregoing difficulties, devices disclosed in U.S. Pat. Nos. 3,828,610 and 3,895,689 to Swearingen entitled Thrust Bearing Lubricant Measurement and Balance were developed. These devices employed the measurement of lubricant pressures as a means of sensing axial thrust. However, it is often desirable to employ a mechanical means for accomplishing such measurement. Furthermore, certain axial displacement of such shafts can be used advantageously to protect the shaft assembly, bearings and seals.